It is desired to estimate the exposure of persons to media displays which are often displayed in outdoor settings, such as along roads, highways, railways and walkways, as well as in various indoor settings, such as in malls, subway stations, railway stations, bus stations, airports, building lobbies, etc. Moreover, in addition to information concerning the numbers of persons exposed to such media displays, information concerning the days and times such exposure takes place and information concerning the particular individuals so exposed is also highly desired.
It has been proposed to employ global positioning satellite (GPS) systems to track the positions of persons during a period of time, and then to compare the paths of the tracked persons with the known locations of billboards in order to determine which billboards the tracked persons passed by.
This proposed technique, however, suffers from a number of disadvantages. One such disadvantage is that the technique is limited to outdoor use only due to the drastic weakening of GPS signals caused by building structures and the like. As such, the exposure to media displays displayed in indoor settings, such as in malls, subway stations, railway stations, bus stations, airports, building lobbies, etc., cannot be accurately measured using this proposed system. A related disadvantage is that the GPS signals may become weakened when the persons being monitored are traveling in vehicles, such as cars, trucks, buses, trains and the like. As such, the accurate measurement of exposure to even outdoor media displays may not always be possible using this proposed system.
Still another disadvantage of the proposed GPS system is that GPS systems may be costly to implement or maintain. The cost of the electronics required to receive the GPS signals and to convert those GPS signals into location data may be prohibitive, particularly when surveys designed for a large survey population are desired. Moreover, the physical size and weight of the electronics required to receive, process and store the GPS signals may also be prohibitive, since the device must be carried on the person of survey participants at all times for accurate results.
Yet another disadvantage of the proposed GPS system is that although the proposed system may include a monitor having a motion detector for shutting the monitor down when the monitor is not moving (for example, when it is taken off the survey participant during sleep or the like), the monitor is substantially continuously monitoring for location data when the survey participant is moving around. This may not be necessary, for example when the survey participant is in an area with no media displays, and unnecessarily decreases battery life, requiring replacement or recharging of the batteries at shorter intervals.
Each embodiment of the present invention, as discussed in more detail below, obviates at least some of the disadvantages of the proposed GPS system.